Improvement in burglar-alarms



UNITED STATES PATENT CFEICE.

IMPROVEMENT IN BURGLAR-ALARMS.

Specification forming part of Letters Patent No. 118,345, dated August 22, 1871.

To all whom 'it may concern:

VBe it known that I, THOMAS P. CoULsToN, of Philadelphia, county of Philadelphia, State of Pennsylvania, have invented an Improved Burglar-Alarm, of which the following is a specification:

My invention consists of a burglar-alarm, too fully explained hereafter to need preliminary description, the device being adapted for ready at tachment to a door-frame, and arranged to sound an alarm on any attempt being made to open the door, and being of such small size and compact arrangement that it can be readily carried about in the pocket, it being, therefore, especially adapted for the use of travelers.

Figure l is a sectional plan view of my improved burglanalarm attached to a door-frame; Fig. 2, the same, with the working parts in a diferent position; and Fig. 3, an edge view.

A represents part of a door-frame; B, part of a door opening in the direction of the arrow; and C, the frame of my improved burglar-alarm, consisting of a box-like metal casting furnished with a detachable cap, a, and having two flan ges, b and b', at its opposite ends, the latter of these flanges being provided with a set-screw, d, which. is screwed against one edge of the door-frame, in order to draw the flange b tightly against the opposite edge, and thus secure the alarm firmly to the frame. Within and upon the case or frame O of the alarm is arranged an ordinary gunlock, consisting of a mainspring, c, hammer j', springtrigger g, and nipple or tube h, upon which to place a cap to be discharged by a blow from the hammer. The trigger is operated through the medium of a lever, K, hung to the case G, and having at its outer end an opening for the reception of a split pin or key, m, which projects outward beyond the edge of the door and forms, when thus attached to the lever, an operating arm for the same. When the alarm is attached to a door-frame, as above described, a cap placed upon the nipple, the hammer cocked, and the pin m inserted into the opening in the end of the lever. K, any attempt to open the door in the direction of the arrow will cause the said door to strike the pin m, turn the lever K, operate the trigger, and thus release the hammer and explode the cap, the report being sufficient to attract the attention of the occupant ofthe room to the attempt made to open the door. The pin m is attached to the case of the alarm by a chain or cord, x, and can be withdrawn from the opening in the lever K, and either be permitted to hang loosely or be inserted into an opening in the case formed to receive it. When the operating-pin is thus withdrawn-from the lever the door can be opened and closed without striking against or bein g in any way interfered with by the alarm, so that there will be no necessity of removing and replacing the latter when the door has to be opened or closed.

The method of securing thel alarm in position by means of the iianges b and b and setscrew d enables it to be readily secured to door-frames of any width, and to be as readily detached from the same when no longer required, and, the device being of small size and compact arrangement, can be carried about in the pocket and is always ready for use.

I claiml. The within described burglaralarm, arranged for attachment to a door-frame by means of flanges b and b and set-screw d, substantially as herein set forth.

2. rIhe detachable pin m, adapted to the operating-lever K of the alarm, and arranged to be struck and turned by the door, substantially as herein described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

THOS. P. GOULSTON.

Witnesses:

WM. A. STEEL, JOHN K. RUPERTUS. 

